diff --git a/av1/encoder/x86/pickrst_avx2.c b/av1/encoder/x86/pickrst_avx2.c
index 01ba167..3452f73 100644
--- a/av1/encoder/x86/pickrst_avx2.c
+++ b/av1/encoder/x86/pickrst_avx2.c
@@ -19,6 +19,179 @@
 #include "av1/common/restoration.h"
 #include "av1/encoder/pickrst.h"
 
+static INLINE void acc_stat_avx2(int32_t *dst, const uint8_t *src,
+                                 const __m128i *shuffle, const __m256i *kl) {
+  const __m128i s = _mm_shuffle_epi8(xx_loadu_128(src), *shuffle);
+  const __m256i d0 = _mm256_madd_epi16(*kl, _mm256_cvtepu8_epi16(s));
+  const __m256i dst0 = yy_load_256(dst);
+  const __m256i r0 = _mm256_add_epi32(dst0, d0);
+  yy_store_256(dst, r0);
+}
+
+static INLINE void acc_stat_win7_one_line_avx2(
+    const uint8_t *dgd, const uint8_t *src, int h_start, int h_end,
+    int dgd_stride, const __m128i *shuffle, int32_t *sumX,
+    int32_t sumY[WIENER_WIN][WIENER_WIN], int32_t M_int[WIENER_WIN][WIENER_WIN],
+    int32_t H_int[WIENER_WIN2][WIENER_WIN * 8]) {
+  int j, k, l;
+  const int wiener_win = WIENER_WIN;
+  // Main loop handles two pixels at a time
+  // We can assume that h_start is even, since it will always be aligned to
+  // a tile edge + some number of restoration units, and both of those will
+  // be 64-pixel aligned.
+  // However, at the edge of the image, h_end may be odd, so we need to handle
+  // that case correctly.
+  assert(h_start % 2 == 0);
+  const int h_end_even = h_end & ~1;
+  const int has_odd_pixel = h_end & 1;
+  for (j = h_start; j < h_end_even; j += 2) {
+    const uint8_t X1 = src[j];
+    const uint8_t X2 = src[j + 1];
+    *sumX += X1 + X2;
+    const uint8_t *dgd_ij = dgd + j;
+    for (k = 0; k < wiener_win; k++) {
+      const uint8_t *dgd_ijk = dgd_ij + k * dgd_stride;
+      for (l = 0; l < wiener_win; l++) {
+        int32_t *H_ = &H_int[(l * wiener_win + k)][0];
+        const uint8_t D1 = dgd_ijk[l];
+        const uint8_t D2 = dgd_ijk[l + 1];
+        sumY[k][l] += D1 + D2;
+        M_int[k][l] += D1 * X1 + D2 * X2;
+
+        const __m256i kl =
+            _mm256_cvtepu8_epi16(_mm_set1_epi16(loadu_int16(dgd_ijk + l)));
+        acc_stat_avx2(H_ + 0 * 8, dgd_ij + 0 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 1 * 8, dgd_ij + 1 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 2 * 8, dgd_ij + 2 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 3 * 8, dgd_ij + 3 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 4 * 8, dgd_ij + 4 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 5 * 8, dgd_ij + 5 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 6 * 8, dgd_ij + 6 * dgd_stride, shuffle, &kl);
+      }
+    }
+  }
+  // If the width is odd, add in the final pixel
+  if (has_odd_pixel) {
+    const uint8_t X1 = src[j];
+    *sumX += X1;
+    const uint8_t *dgd_ij = dgd + j;
+    for (k = 0; k < wiener_win; k++) {
+      const uint8_t *dgd_ijk = dgd_ij + k * dgd_stride;
+      for (l = 0; l < wiener_win; l++) {
+        int32_t *H_ = &H_int[(l * wiener_win + k)][0];
+        const uint8_t D1 = dgd_ijk[l];
+        sumY[k][l] += D1;
+        M_int[k][l] += D1 * X1;
+
+        // The `acc_stat_avx2` function wants its input to have interleaved
+        // copies of two pixels, but we only have one. However, the pixels
+        // are (effectively) used as inputs to a multiply-accumulate.
+        // So if we set the extra pixel slot to 0, then it is effectively
+        // ignored.
+        const __m256i kl = _mm256_cvtepu8_epi16(_mm_set1_epi16((int16_t)D1));
+        acc_stat_avx2(H_ + 0 * 8, dgd_ij + 0 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 1 * 8, dgd_ij + 1 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 2 * 8, dgd_ij + 2 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 3 * 8, dgd_ij + 3 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 4 * 8, dgd_ij + 4 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 5 * 8, dgd_ij + 5 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 6 * 8, dgd_ij + 6 * dgd_stride, shuffle, &kl);
+      }
+    }
+  }
+}
+
+static INLINE void compute_stats_win7_opt_avx2(
+    const uint8_t *dgd, const uint8_t *src, int h_start, int h_end, int v_start,
+    int v_end, int dgd_stride, int src_stride, int64_t *M, int64_t *H,
+    int use_downsampled_wiener_stats) {
+  int i, j, k, l, m, n;
+  const int wiener_win = WIENER_WIN;
+  const int pixel_count = (h_end - h_start) * (v_end - v_start);
+  const int wiener_win2 = wiener_win * wiener_win;
+  const int wiener_halfwin = (wiener_win >> 1);
+  uint8_t avg = find_average(dgd, h_start, h_end, v_start, v_end, dgd_stride);
+
+  int32_t M_int32[WIENER_WIN][WIENER_WIN] = { { 0 } };
+  int64_t M_int64[WIENER_WIN][WIENER_WIN] = { { 0 } };
+  int32_t M_int32_row[WIENER_WIN][WIENER_WIN] = { { 0 } };
+
+  DECLARE_ALIGNED(32, int32_t,
+                  H_int32[WIENER_WIN2][WIENER_WIN * 8]) = { { 0 } };
+  DECLARE_ALIGNED(32, int32_t,
+                  H_int32_row[WIENER_WIN2][WIENER_WIN * 8]) = { { 0 } };
+  int64_t H_int64[WIENER_WIN2][WIENER_WIN * 8] = { { 0 } };
+  int32_t sumY[WIENER_WIN][WIENER_WIN] = { { 0 } };
+  int32_t sumX = 0;
+  const uint8_t *dgd_win = dgd - wiener_halfwin * dgd_stride - wiener_halfwin;
+  int downsample_factor =
+      use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;
+  int32_t sumX_row = 0;
+  int32_t sumY_row[WIENER_WIN][WIENER_WIN] = { { 0 } };
+
+  const __m128i shuffle = xx_loadu_128(g_shuffle_stats_data);
+  for (j = v_start; j < v_end; j += 64) {
+    const int vert_end = AOMMIN(64, v_end - j) + j;
+    for (i = j; i < vert_end; i = i + downsample_factor) {
+      if (use_downsampled_wiener_stats &&
+          (vert_end - i < WIENER_STATS_DOWNSAMPLE_FACTOR)) {
+        downsample_factor = vert_end - i;
+      }
+      sumX_row = 0;
+      memset(sumY_row, 0, sizeof(int32_t) * WIENER_WIN * WIENER_WIN);
+      memset(M_int32_row, 0, sizeof(int32_t) * WIENER_WIN * WIENER_WIN);
+      memset(H_int32_row, 0, sizeof(int32_t) * WIENER_WIN2 * (WIENER_WIN * 8));
+      acc_stat_win7_one_line_avx2(
+          dgd_win + i * dgd_stride, src + i * src_stride, h_start, h_end,
+          dgd_stride, &shuffle, &sumX_row, sumY_row, M_int32_row, H_int32_row);
+      sumX += sumX_row * downsample_factor;
+
+      // Scale M matrix based on the downsampling factor
+      for (k = 0; k < wiener_win; ++k) {
+        for (l = 0; l < wiener_win; ++l) {
+          sumY[k][l] += (sumY_row[k][l] * downsample_factor);
+          M_int32[k][l] += (M_int32_row[k][l] * downsample_factor);
+        }
+      }
+      // Scale H matrix based on the downsampling factor
+      for (k = 0; k < WIENER_WIN2; ++k) {
+        for (l = 0; l < WIENER_WIN * 8; ++l) {
+          H_int32[k][l] += (H_int32_row[k][l] * downsample_factor);
+        }
+      }
+    }
+    for (k = 0; k < wiener_win; ++k) {
+      for (l = 0; l < wiener_win; ++l) {
+        M_int64[k][l] += M_int32[k][l];
+        M_int32[k][l] = 0;
+      }
+    }
+    for (k = 0; k < WIENER_WIN2; ++k) {
+      for (l = 0; l < WIENER_WIN * 8; ++l) {
+        H_int64[k][l] += H_int32[k][l];
+        H_int32[k][l] = 0;
+      }
+    }
+  }
+
+  const int64_t avg_square_sum = (int64_t)avg * (int64_t)avg * pixel_count;
+  for (k = 0; k < wiener_win; k++) {
+    for (l = 0; l < wiener_win; l++) {
+      const int32_t idx0 = l * wiener_win + k;
+      M[idx0] =
+          M_int64[k][l] + (avg_square_sum - (int64_t)avg * (sumX + sumY[k][l]));
+      int64_t *H_ = H + idx0 * wiener_win2;
+      int64_t *H_int_ = &H_int64[idx0][0];
+      for (m = 0; m < wiener_win; m++) {
+        for (n = 0; n < wiener_win; n++) {
+          H_[m * wiener_win + n] = H_int_[n * 8 + m] + avg_square_sum -
+                                   (int64_t)avg * (sumY[k][l] + sumY[n][m]);
+        }
+      }
+    }
+  }
+}
+
 #if CONFIG_AV1_HIGHBITDEPTH
 static INLINE void acc_stat_highbd_avx2(int64_t *dst, const uint16_t *dgd,
                                         const __m256i *shuffle,
@@ -364,1127 +537,169 @@
 }
 #endif  // CONFIG_AV1_HIGHBITDEPTH
 
-static INLINE void madd_and_accum_avx2(__m256i src, __m256i dgd, __m256i *sum) {
-  *sum = _mm256_add_epi32(*sum, _mm256_madd_epi16(src, dgd));
-}
+static INLINE void acc_stat_win5_one_line_avx2(
+    const uint8_t *dgd, const uint8_t *src, int h_start, int h_end,
+    int dgd_stride, const __m128i *shuffle, int32_t *sumX,
+    int32_t sumY[WIENER_WIN_CHROMA][WIENER_WIN_CHROMA],
+    int32_t M_int[WIENER_WIN_CHROMA][WIENER_WIN_CHROMA],
+    int32_t H_int[WIENER_WIN2_CHROMA][WIENER_WIN_CHROMA * 8]) {
+  int j, k, l;
+  const int wiener_win = WIENER_WIN_CHROMA;
+  // Main loop handles two pixels at a time
+  // We can assume that h_start is even, since it will always be aligned to
+  // a tile edge + some number of restoration units, and both of those will
+  // be 64-pixel aligned.
+  // However, at the edge of the image, h_end may be odd, so we need to handle
+  // that case correctly.
+  assert(h_start % 2 == 0);
+  const int h_end_even = h_end & ~1;
+  const int has_odd_pixel = h_end & 1;
+  for (j = h_start; j < h_end_even; j += 2) {
+    const uint8_t X1 = src[j];
+    const uint8_t X2 = src[j + 1];
+    *sumX += X1 + X2;
+    const uint8_t *dgd_ij = dgd + j;
+    for (k = 0; k < wiener_win; k++) {
+      const uint8_t *dgd_ijk = dgd_ij + k * dgd_stride;
+      for (l = 0; l < wiener_win; l++) {
+        int32_t *H_ = &H_int[(l * wiener_win + k)][0];
+        const uint8_t D1 = dgd_ijk[l];
+        const uint8_t D2 = dgd_ijk[l + 1];
+        sumY[k][l] += D1 + D2;
+        M_int[k][l] += D1 * X1 + D2 * X2;
 
-static INLINE __m256i convert_and_add_avx2(__m256i src) {
-  const __m256i s0 = _mm256_cvtepi32_epi64(_mm256_castsi256_si128(src));
-  const __m256i s1 = _mm256_cvtepi32_epi64(_mm256_extracti128_si256(src, 1));
-  return _mm256_add_epi64(s0, s1);
-}
-
-static INLINE __m256i hadd_four_32_to_64_avx2(__m256i src0, __m256i src1,
-                                              __m256i *src2, __m256i *src3) {
-  // 00 01 10 11 02 03 12 13
-  const __m256i s_0 = _mm256_hadd_epi32(src0, src1);
-  // 20 21 30 31 22 23 32 33
-  const __m256i s_1 = _mm256_hadd_epi32(*src2, *src3);
-  // 00+01 10+11 20+21 30+31 02+03 12+13 22+23 32+33
-  const __m256i s_2 = _mm256_hadd_epi32(s_0, s_1);
-  return convert_and_add_avx2(s_2);
-}
-
-static INLINE __m128i add_64bit_lvl_avx2(__m256i src0, __m256i src1) {
-  // 00 10 02 12
-  const __m256i t0 = _mm256_unpacklo_epi64(src0, src1);
-  // 01 11 03 13
-  const __m256i t1 = _mm256_unpackhi_epi64(src0, src1);
-  // 00+01 10+11 02+03 12+13
-  const __m256i sum = _mm256_add_epi64(t0, t1);
-  // 00+01 10+11
-  const __m128i sum0 = _mm256_castsi256_si128(sum);
-  // 02+03 12+13
-  const __m128i sum1 = _mm256_extracti128_si256(sum, 1);
-  // 00+01+02+03 10+11+12+13
-  return _mm_add_epi64(sum0, sum1);
-}
-
-static INLINE __m128i convert_32_to_64_add_avx2(__m256i src0, __m256i src1) {
-  // 00 01 02 03
-  const __m256i s0 = convert_and_add_avx2(src0);
-  // 10 11 12 13
-  const __m256i s1 = convert_and_add_avx2(src1);
-  return add_64bit_lvl_avx2(s0, s1);
-}
-
-static INLINE int32_t calc_sum_of_register(__m256i src) {
-  const __m128i src_l = _mm256_castsi256_si128(src);
-  const __m128i src_h = _mm256_extracti128_si256(src, 1);
-  const __m128i sum = _mm_add_epi32(src_l, src_h);
-  const __m128i dst0 = _mm_add_epi32(sum, _mm_srli_si128(sum, 8));
-  const __m128i dst1 = _mm_add_epi32(dst0, _mm_srli_si128(dst0, 4));
-  return _mm_cvtsi128_si32(dst1);
-}
-
-static INLINE void transpose_64bit_4x4_avx2(const __m256i *const src,
-                                            __m256i *const dst) {
-  // Unpack 64 bit elements. Goes from:
-  // src[0]: 00 01 02 03
-  // src[1]: 10 11 12 13
-  // src[2]: 20 21 22 23
-  // src[3]: 30 31 32 33
-  // to:
-  // reg0:    00 10 02 12
-  // reg1:    20 30 22 32
-  // reg2:    01 11 03 13
-  // reg3:    21 31 23 33
-  const __m256i reg0 = _mm256_unpacklo_epi64(src[0], src[1]);
-  const __m256i reg1 = _mm256_unpacklo_epi64(src[2], src[3]);
-  const __m256i reg2 = _mm256_unpackhi_epi64(src[0], src[1]);
-  const __m256i reg3 = _mm256_unpackhi_epi64(src[2], src[3]);
-
-  // Unpack 64 bit elements resulting in:
-  // dst[0]: 00 10 20 30
-  // dst[1]: 01 11 21 31
-  // dst[2]: 02 12 22 32
-  // dst[3]: 03 13 23 33
-  dst[0] = _mm256_inserti128_si256(reg0, _mm256_castsi256_si128(reg1), 1);
-  dst[1] = _mm256_inserti128_si256(reg2, _mm256_castsi256_si128(reg3), 1);
-  dst[2] = _mm256_inserti128_si256(reg1, _mm256_extracti128_si256(reg0, 1), 0);
-  dst[3] = _mm256_inserti128_si256(reg3, _mm256_extracti128_si256(reg2, 1), 0);
-}
-
-// When we load 32 values of int8_t type and need less than 32 values for
-// processing, the below mask is used to make the extra values zero.
-static const int8_t mask_8bit[32] = {
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 16 bytes
-  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,   // 16 bytes
-};
-
-// When we load 16 values of int16_t type and need less than 16 values for
-// processing, the below mask is used to make the extra values zero.
-static const int16_t mask_16bit[32] = {
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 16 bytes
-  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,   // 16 bytes
-};
-
-static INLINE uint8_t calc_dgd_buf_avg_avx2(const uint8_t *src, int32_t h_start,
-                                            int32_t h_end, int32_t v_start,
-                                            int32_t v_end, int32_t stride) {
-  const uint8_t *src_temp = src + v_start * stride + h_start;
-  const __m256i zero = _mm256_setzero_si256();
-  const int32_t width = h_end - h_start;
-  const int32_t height = v_end - v_start;
-  const int32_t wd_beyond_mul32 = width & 31;
-  const int32_t wd_mul32 = width - wd_beyond_mul32;
-  __m128i mask_low, mask_high;
-  __m256i ss = zero;
-
-  // When width is not multiple of 32, it still loads 32 and to make the data
-  // which is extra (beyond required) as zero using the below mask.
-  if (wd_beyond_mul32 >= 16) {
-    mask_low = _mm_set1_epi8(-1);
-    mask_high = _mm_loadu_si128((__m128i *)(&mask_8bit[32 - wd_beyond_mul32]));
-  } else {
-    mask_low = _mm_loadu_si128((__m128i *)(&mask_8bit[16 - wd_beyond_mul32]));
-    mask_high = _mm_setzero_si128();
+        const __m256i kl =
+            _mm256_cvtepu8_epi16(_mm_set1_epi16(loadu_int16(dgd_ijk + l)));
+        acc_stat_avx2(H_ + 0 * 8, dgd_ij + 0 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 1 * 8, dgd_ij + 1 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 2 * 8, dgd_ij + 2 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 3 * 8, dgd_ij + 3 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 4 * 8, dgd_ij + 4 * dgd_stride, shuffle, &kl);
+      }
+    }
   }
-  const __m256i mask =
-      _mm256_inserti128_si256(_mm256_castsi128_si256(mask_low), mask_high, 1);
+  // If the width is odd, add in the final pixel
+  if (has_odd_pixel) {
+    const uint8_t X1 = src[j];
+    *sumX += X1;
+    const uint8_t *dgd_ij = dgd + j;
+    for (k = 0; k < wiener_win; k++) {
+      const uint8_t *dgd_ijk = dgd_ij + k * dgd_stride;
+      for (l = 0; l < wiener_win; l++) {
+        int32_t *H_ = &H_int[(l * wiener_win + k)][0];
+        const uint8_t D1 = dgd_ijk[l];
+        sumY[k][l] += D1;
+        M_int[k][l] += D1 * X1;
 
-  int32_t proc_ht = 0;
-  do {
-    // Process width in multiple of 32.
-    int32_t proc_wd = 0;
-    while (proc_wd < wd_mul32) {
-      const __m256i s_0 = _mm256_loadu_si256((__m256i *)(src_temp + proc_wd));
-      const __m256i sad_0 = _mm256_sad_epu8(s_0, zero);
-      ss = _mm256_add_epi32(ss, sad_0);
-      proc_wd += 32;
-    }
-
-    // Process the remaining width.
-    if (wd_beyond_mul32) {
-      const __m256i s_0 = _mm256_loadu_si256((__m256i *)(src_temp + proc_wd));
-      const __m256i s_m_0 = _mm256_and_si256(s_0, mask);
-      const __m256i sad_0 = _mm256_sad_epu8(s_m_0, zero);
-      ss = _mm256_add_epi32(ss, sad_0);
-    }
-    src_temp += stride;
-    proc_ht++;
-  } while (proc_ht < height);
-
-  const uint32_t sum = calc_sum_of_register(ss);
-  const uint8_t avg = sum / (width * height);
-  return avg;
-}
-
-// Fill (src-avg) or (dgd-avg) buffers. Note that when n = (width % 16) is not
-// 0, it writes (16 - n) more data than required.
-static INLINE void sub_avg_block_avx2(const uint8_t *src,
-                                      const int32_t src_stride,
-                                      const uint8_t avg, const int32_t width,
-                                      const int32_t height, int16_t *dst,
-                                      const int32_t dst_stride,
-                                      int use_downsampled_wiener_stats) {
-  const __m256i avg_reg = _mm256_set1_epi16(avg);
-
-  int32_t proc_ht = 0;
-  do {
-    int ds_factor =
-        use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;
-    if (use_downsampled_wiener_stats &&
-        (height - proc_ht < WIENER_STATS_DOWNSAMPLE_FACTOR)) {
-      ds_factor = height - proc_ht;
-    }
-
-    int32_t proc_wd = 0;
-    while (proc_wd < width) {
-      const __m128i s = _mm_loadu_si128((__m128i *)(src + proc_wd));
-      const __m256i ss = _mm256_cvtepu8_epi16(s);
-      const __m256i d = _mm256_sub_epi16(ss, avg_reg);
-      _mm256_storeu_si256((__m256i *)(dst + proc_wd), d);
-      proc_wd += 16;
-    }
-
-    src += ds_factor * src_stride;
-    dst += ds_factor * dst_stride;
-    proc_ht += ds_factor;
-  } while (proc_ht < height);
-}
-
-// Fills lower-triangular elements of H buffer from upper triangular elements of
-// the same
-static INLINE void fill_lower_triag_elements_avx2(const int32_t wiener_win2,
-                                                  int64_t *const H) {
-  for (int32_t i = 0; i < wiener_win2 - 1; i += 4) {
-    __m256i in[4], out[4];
-
-    in[0] = _mm256_loadu_si256((__m256i *)(H + (i + 0) * wiener_win2 + i + 1));
-    in[1] = _mm256_loadu_si256((__m256i *)(H + (i + 1) * wiener_win2 + i + 1));
-    in[2] = _mm256_loadu_si256((__m256i *)(H + (i + 2) * wiener_win2 + i + 1));
-    in[3] = _mm256_loadu_si256((__m256i *)(H + (i + 3) * wiener_win2 + i + 1));
-
-    transpose_64bit_4x4_avx2(in, out);
-
-    _mm_storel_epi64((__m128i *)(H + (i + 1) * wiener_win2 + i),
-                     _mm256_castsi256_si128(out[0]));
-    _mm_storeu_si128((__m128i *)(H + (i + 2) * wiener_win2 + i),
-                     _mm256_castsi256_si128(out[1]));
-    _mm256_storeu_si256((__m256i *)(H + (i + 3) * wiener_win2 + i), out[2]);
-    _mm256_storeu_si256((__m256i *)(H + (i + 4) * wiener_win2 + i), out[3]);
-
-    for (int32_t j = i + 5; j < wiener_win2; j += 4) {
-      in[0] = _mm256_loadu_si256((__m256i *)(H + (i + 0) * wiener_win2 + j));
-      in[1] = _mm256_loadu_si256((__m256i *)(H + (i + 1) * wiener_win2 + j));
-      in[2] = _mm256_loadu_si256((__m256i *)(H + (i + 2) * wiener_win2 + j));
-      in[3] = _mm256_loadu_si256((__m256i *)(H + (i + 3) * wiener_win2 + j));
-
-      transpose_64bit_4x4_avx2(in, out);
-
-      _mm256_storeu_si256((__m256i *)(H + (j + 0) * wiener_win2 + i), out[0]);
-      _mm256_storeu_si256((__m256i *)(H + (j + 1) * wiener_win2 + i), out[1]);
-      _mm256_storeu_si256((__m256i *)(H + (j + 2) * wiener_win2 + i), out[2]);
-      _mm256_storeu_si256((__m256i *)(H + (j + 3) * wiener_win2 + i), out[3]);
+        // The `acc_stat_avx2` function wants its input to have interleaved
+        // copies of two pixels, but we only have one. However, the pixels
+        // are (effectively) used as inputs to a multiply-accumulate.
+        // So if we set the extra pixel slot to 0, then it is effectively
+        // ignored.
+        const __m256i kl = _mm256_cvtepu8_epi16(_mm_set1_epi16((int16_t)D1));
+        acc_stat_avx2(H_ + 0 * 8, dgd_ij + 0 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 1 * 8, dgd_ij + 1 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 2 * 8, dgd_ij + 2 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 3 * 8, dgd_ij + 3 * dgd_stride, shuffle, &kl);
+        acc_stat_avx2(H_ + 4 * 8, dgd_ij + 4 * dgd_stride, shuffle, &kl);
+      }
     }
   }
 }
 
-// Fill H buffer based on loop_count.
-#define INIT_H_VALUES(d, loop_count)                                          \
-  for (int g = 0; g < loop_count; g++) {                                      \
-    const __m256i dgd0 = _mm256_loadu_si256((__m256i *)(d + (g * d_stride))); \
-    madd_and_accum_avx2(dgd_mul_df, dgd0, &sum_h[g]);                         \
-  }
+static INLINE void compute_stats_win5_opt_avx2(
+    const uint8_t *dgd, const uint8_t *src, int h_start, int h_end, int v_start,
+    int v_end, int dgd_stride, int src_stride, int64_t *M, int64_t *H,
+    int use_downsampled_wiener_stats) {
+  int i, j, k, l, m, n;
+  const int wiener_win = WIENER_WIN_CHROMA;
+  const int pixel_count = (h_end - h_start) * (v_end - v_start);
+  const int wiener_win2 = wiener_win * wiener_win;
+  const int wiener_halfwin = (wiener_win >> 1);
+  uint8_t avg = find_average(dgd, h_start, h_end, v_start, v_end, dgd_stride);
 
-// Fill M & H buffer.
-#define INIT_MH_VALUES(d)                                    \
-  for (int g = 0; g < wiener_win; g++) {                     \
-    const __m256i dgds_0 =                                   \
-        _mm256_loadu_si256((__m256i *)(d + (g * d_stride))); \
-    madd_and_accum_avx2(src_mul_df, dgds_0, &sum_m[g]);      \
-    madd_and_accum_avx2(dgd_mul_df, dgds_0, &sum_h[g]);      \
-  }
+  int32_t M_int32[WIENER_WIN_CHROMA][WIENER_WIN_CHROMA] = { { 0 } };
+  int32_t M_int32_row[WIENER_WIN_CHROMA][WIENER_WIN_CHROMA] = { { 0 } };
+  int64_t M_int64[WIENER_WIN_CHROMA][WIENER_WIN_CHROMA] = { { 0 } };
+  DECLARE_ALIGNED(
+      32, int32_t,
+      H_int32[WIENER_WIN2_CHROMA][WIENER_WIN_CHROMA * 8]) = { { 0 } };
+  DECLARE_ALIGNED(
+      32, int32_t,
+      H_int32_row[WIENER_WIN2_CHROMA][WIENER_WIN_CHROMA * 8]) = { { 0 } };
+  int64_t H_int64[WIENER_WIN2_CHROMA][WIENER_WIN_CHROMA * 8] = { { 0 } };
+  int32_t sumY[WIENER_WIN_CHROMA][WIENER_WIN_CHROMA] = { { 0 } };
+  int32_t sumX = 0;
+  const uint8_t *dgd_win = dgd - wiener_halfwin * dgd_stride - wiener_halfwin;
+  int downsample_factor =
+      use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;
+  int32_t sumX_row = 0;
+  int32_t sumY_row[WIENER_WIN_CHROMA][WIENER_WIN_CHROMA] = { { 0 } };
 
-// Update the dgd pointers appropriately.
-#define INITIALIZATION(wiener_window_sz)                                      \
-  j = i / wiener_window_sz;                                                   \
-  const int16_t *d_window = d + j;                                            \
-  const int16_t *d_current_row = d + j + ((i % wiener_window_sz) * d_stride); \
-  int proc_ht = v_start;                                                      \
-  downsample_factor =                                                         \
-      use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;      \
-  __m256i sum_h[wiener_window_sz];                                            \
-  memset(sum_h, 0, sizeof(sum_h));
-
-// Update the downsample factor appropriately.
-#define UPDATE_DOWNSAMPLE_FACTOR                              \
-  int proc_wd = 0;                                            \
-  if (use_downsampled_wiener_stats &&                         \
-      ((v_end - proc_ht) < WIENER_STATS_DOWNSAMPLE_FACTOR)) { \
-    downsample_factor = v_end - proc_ht;                      \
-  }                                                           \
-  const __m256i df_reg = _mm256_set1_epi16(downsample_factor);
-
-#define CALCULATE_REMAINING_H_WIN5                                             \
-  while (j < wiener_win) {                                                     \
-    d_window = d;                                                              \
-    d_current_row = d + (i / wiener_win) + ((i % wiener_win) * d_stride);      \
-    const __m256i zero = _mm256_setzero_si256();                               \
-    sum_h[0] = zero;                                                           \
-    sum_h[1] = zero;                                                           \
-    sum_h[2] = zero;                                                           \
-    sum_h[3] = zero;                                                           \
-    sum_h[4] = zero;                                                           \
-                                                                               \
-    proc_ht = v_start;                                                         \
-    downsample_factor =                                                        \
-        use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;     \
-    do {                                                                       \
-      UPDATE_DOWNSAMPLE_FACTOR;                                                \
-                                                                               \
-      /* Process the amount of width multiple of 16.*/                         \
-      while (proc_wd < wd_mul16) {                                             \
-        const __m256i dgd =                                                    \
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));          \
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);            \
-        INIT_H_VALUES(d_window + j + proc_wd, 5)                               \
-                                                                               \
-        proc_wd += 16;                                                         \
-      };                                                                       \
-                                                                               \
-      /* Process the remaining width here. */                                  \
-      if (wd_beyond_mul16) {                                                   \
-        const __m256i dgd =                                                    \
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));          \
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);                  \
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);       \
-        INIT_H_VALUES(d_window + j + proc_wd, 5)                               \
-      }                                                                        \
-      proc_ht += downsample_factor;                                            \
-      d_window += downsample_factor * d_stride;                                \
-      d_current_row += downsample_factor * d_stride;                           \
-    } while (proc_ht < v_end);                                                 \
-    const __m256i s_h0 =                                                       \
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);     \
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + (wiener_win * j)), \
-                        s_h0);                                                 \
-    const __m256i s_m_h = convert_and_add_avx2(sum_h[4]);                      \
-    const __m128i s_m_h0 = add_64bit_lvl_avx2(s_m_h, s_m_h);                   \
-    _mm_storel_epi64(                                                          \
-        (__m128i *)(H + (i * wiener_win2) + (wiener_win * j) + 4), s_m_h0);    \
-    j++;                                                                       \
-  }
-
-#define CALCULATE_REMAINING_H_WIN7                                             \
-  while (j < wiener_win) {                                                     \
-    d_window = d;                                                              \
-    d_current_row = d + (i / wiener_win) + ((i % wiener_win) * d_stride);      \
-    const __m256i zero = _mm256_setzero_si256();                               \
-    sum_h[0] = zero;                                                           \
-    sum_h[1] = zero;                                                           \
-    sum_h[2] = zero;                                                           \
-    sum_h[3] = zero;                                                           \
-    sum_h[4] = zero;                                                           \
-    sum_h[5] = zero;                                                           \
-    sum_h[6] = zero;                                                           \
-                                                                               \
-    proc_ht = v_start;                                                         \
-    downsample_factor =                                                        \
-        use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;     \
-    do {                                                                       \
-      UPDATE_DOWNSAMPLE_FACTOR;                                                \
-                                                                               \
-      /* Process the amount of width multiple of 16.*/                         \
-      while (proc_wd < wd_mul16) {                                             \
-        const __m256i dgd =                                                    \
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));          \
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);            \
-        INIT_H_VALUES(d_window + j + proc_wd, 7)                               \
-                                                                               \
-        proc_wd += 16;                                                         \
-      };                                                                       \
-                                                                               \
-      /* Process the remaining width here. */                                  \
-      if (wd_beyond_mul16) {                                                   \
-        const __m256i dgd =                                                    \
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));          \
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);                  \
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);       \
-        INIT_H_VALUES(d_window + j + proc_wd, 7)                               \
-      }                                                                        \
-      proc_ht += downsample_factor;                                            \
-      d_window += downsample_factor * d_stride;                                \
-      d_current_row += downsample_factor * d_stride;                           \
-    } while (proc_ht < v_end);                                                 \
-    const __m256i s_h1 =                                                       \
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);     \
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + (wiener_win * j)), \
-                        s_h1);                                                 \
-    const __m256i s_h2 =                                                       \
-        hadd_four_32_to_64_avx2(sum_h[4], sum_h[5], &sum_h[6], &sum_h[6]);     \
-    _mm256_storeu_si256(                                                       \
-        (__m256i *)(H + (i * wiener_win2) + (wiener_win * j) + 4), s_h2);      \
-    j++;                                                                       \
-  }
-
-// The buffers H(auto-covariance) and M(cross-correlation) are used to estimate
-// the filter tap values required for wiener filtering. Here, the buffer H is of
-// size ((wiener_window_size^2)*(wiener_window_size^2)) and M is of size
-// (wiener_window_size*wiener_window_size). H is a symmetric matrix where the
-// value above the diagonal (upper triangle) are equal to the values below the
-// diagonal (lower triangle). The calculation of elements/stats of H(upper
-// triangle) and M is done in steps as described below where each step fills
-// specific values of H and M.
-// Once the upper triangular elements of H matrix are derived, the same will be
-// copied to lower triangular using the function
-// fill_lower_triag_elements_avx2().
-// Example: Wiener window size =
-// WIENER_WIN_CHROMA (5) M buffer = [M0 M1 M2 ---- M23 M24] H buffer = Hxy
-// (x-row, y-column) [H00 H01 H02 ---- H023 H024] [H10 H11 H12 ---- H123 H124]
-// [H30 H31 H32 ---- H323 H324]
-// [H40 H41 H42 ---- H423 H424]
-// [H50 H51 H52 ---- H523 H524]
-// [H60 H61 H62 ---- H623 H624]
-//            ||
-//            ||
-// [H230 H231 H232 ---- H2323 H2324]
-// [H240 H241 H242 ---- H2423 H2424]
-// In Step 1, whole M buffers (i.e., M0 to M24) and the first row of H (i.e.,
-// H00 to H024) is filled. The remaining rows of H buffer are filled through
-// steps 2 to 6.
-static void compute_stats_win5_avx2(
-    const int16_t *const d, const int32_t d_stride, const int16_t *const s,
-    const int32_t s_stride, const int32_t width, int v_start, int v_end,
-    int64_t *const M, int64_t *H, int use_downsampled_wiener_stats) {
-  const int32_t wiener_win = WIENER_WIN_CHROMA;
-  const int32_t wiener_win2 = wiener_win * wiener_win;
-  // Amount of width which is beyond multiple of 16. This case is handled
-  // appropriately to process only the required width towards the end.
-  const int32_t wd_mul16 = width & ~15;
-  const int32_t wd_beyond_mul16 = width - wd_mul16;
-  const __m256i mask =
-      _mm256_loadu_si256((__m256i *)(&mask_16bit[16 - wd_beyond_mul16]));
-  int downsample_factor;
-
-  // Step 1: Full M (i.e., M0 to M24) and first row H (i.e., H00 to H024)
-  // values are filled here. Here, the loop over 'j' is executed for values 0
-  // to 4 (wiener_win-1). When the loop executed for a specific 'j', 5 values of
-  // M and H are filled as shown below.
-  // j=0: M0-M4 and H00-H04, j=1: M5-M9 and H05-H09 are filled etc,.
-  int j = 0;
-  do {
-    const int16_t *s_t = s;
-    const int16_t *d_t = d;
-    __m256i sum_m[WIENER_WIN_CHROMA] = { _mm256_setzero_si256() };
-    __m256i sum_h[WIENER_WIN_CHROMA] = { _mm256_setzero_si256() };
-    downsample_factor =
-        use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;
-    int proc_ht = v_start;
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i src = _mm256_loadu_si256((__m256i *)(s_t + proc_wd));
-        const __m256i dgd = _mm256_loadu_si256((__m256i *)(d_t + proc_wd));
-        const __m256i src_mul_df = _mm256_mullo_epi16(src, df_reg);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_MH_VALUES(d_t + j + proc_wd)
-
-        proc_wd += 16;
+  const __m128i shuffle = xx_loadu_128(g_shuffle_stats_data);
+  for (j = v_start; j < v_end; j += 64) {
+    const int vert_end = AOMMIN(64, v_end - j) + j;
+    for (i = j; i < vert_end; i = i + downsample_factor) {
+      if (use_downsampled_wiener_stats &&
+          (vert_end - i < WIENER_STATS_DOWNSAMPLE_FACTOR)) {
+        downsample_factor = vert_end - i;
       }
+      sumX_row = 0;
+      memset(sumY_row, 0,
+             sizeof(int32_t) * WIENER_WIN_CHROMA * WIENER_WIN_CHROMA);
+      memset(M_int32_row, 0,
+             sizeof(int32_t) * WIENER_WIN_CHROMA * WIENER_WIN_CHROMA);
+      memset(H_int32_row, 0,
+             sizeof(int32_t) * WIENER_WIN2_CHROMA * (WIENER_WIN_CHROMA * 8));
+      acc_stat_win5_one_line_avx2(
+          dgd_win + i * dgd_stride, src + i * src_stride, h_start, h_end,
+          dgd_stride, &shuffle, &sumX_row, sumY_row, M_int32_row, H_int32_row);
+      sumX += sumX_row * downsample_factor;
 
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i src = _mm256_loadu_si256((__m256i *)(s_t + proc_wd));
-        const __m256i dgd = _mm256_loadu_si256((__m256i *)(d_t + proc_wd));
-        const __m256i src_mask = _mm256_and_si256(src, mask);
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i src_mul_df = _mm256_mullo_epi16(src_mask, df_reg);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_MH_VALUES(d_t + j + proc_wd)
-      }
-      proc_ht += downsample_factor;
-      s_t += downsample_factor * s_stride;
-      d_t += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-
-    const __m256i s_m =
-        hadd_four_32_to_64_avx2(sum_m[0], sum_m[1], &sum_m[2], &sum_m[3]);
-    const __m128i s_m_h = convert_32_to_64_add_avx2(sum_m[4], sum_h[4]);
-    _mm256_storeu_si256((__m256i *)(M + wiener_win * j), s_m);
-    _mm_storel_epi64((__m128i *)&M[wiener_win * j + 4], s_m_h);
-
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    _mm256_storeu_si256((__m256i *)(H + wiener_win * j), s_h);
-    _mm_storeh_epi64((__m128i *)&H[wiener_win * j + 4], s_m_h);
-  } while (++j < wiener_win);
-
-  // The below steps are designed to fill remaining rows of H buffer. Here, aim
-  // is to fill only upper triangle elements correspond to each row and lower
-  // triangle elements are copied from upper-triangle elements. Also, as
-  // mentioned in Step 1, the core function is designed to fill 5
-  // elements/stats/values of H buffer.
-  //
-  // Step 2: Here, the rows 1, 6, 11, 16 and 21 are filled. As we need to fill
-  // only upper-triangle elements, H10 from row1, H60-H64 and H65 from row6,etc,
-  // are need not be filled. As the core function process 5 values, in first
-  // iteration of 'j' only 4 values to be filled i.e., H11-H14 from row1,H66-H69
-  // from row6, etc.
-  for (int i = 1; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN_CHROMA)
-
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (1 * d_stride), 4)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (1 * d_stride), 4)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + i), s_h);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN5
-  }
-
-  // Step 3: Here, the rows 2, 7, 12, 17 and 22 are filled. As we need to fill
-  // only upper-triangle elements, H20-H21 from row2, H70-H74 and H75-H76 from
-  // row7, etc, are need not be filled. As the core function process 5 values,
-  // in first iteration of 'j' only 3 values to be filled i.e., H22-H24 from
-  // row2, H77-H79 from row7, etc.
-  for (int i = 2; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN_CHROMA)
-
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (2 * d_stride), 3)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (2 * d_stride), 3)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + i), s_h);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN5
-  }
-
-  // Step 4: Here, the rows 3, 8, 13, 18 and 23 are filled. As we need to fill
-  // only upper-triangle elements, H30-H32 from row3, H80-H84 and H85-H87 from
-  // row8, etc, are need not be filled. As the core function process 5 values,
-  // in first iteration of 'j' only 2 values to be filled i.e., H33-H34 from
-  // row3, H88-89 from row8, etc.
-  for (int i = 3; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN_CHROMA)
-
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (3 * d_stride), 2)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (3 * d_stride), 2)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m128i s_h = convert_32_to_64_add_avx2(sum_h[0], sum_h[1]);
-    _mm_storeu_si128((__m128i *)(H + (i * wiener_win2) + i), s_h);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN5
-  }
-
-  // Step 5: Here, the rows 4, 9, 14, 19 and 24 are filled. As we need to fill
-  // only upper-triangle elements, H40-H43 from row4, H90-H94 and H95-H98 from
-  // row9, etc, are need not be filled. As the core function process 5 values,
-  // in first iteration of 'j' only 1 values to be filled i.e., H44 from row4,
-  // H99 from row9, etc.
-  for (int i = 4; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN_CHROMA)
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (4 * d_stride), 1)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (4 * d_stride), 1)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m128i s_h = convert_32_to_64_add_avx2(sum_h[0], sum_h[1]);
-    _mm_storeu_si128((__m128i *)(H + (i * wiener_win2) + i), s_h);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN5
-  }
-
-  // Step 6: Here, the rows 5, 10, 15 and 20 are filled. As we need to fill only
-  // upper-triangle elements, H50-H54 from row5, H100-H104 and H105-H109 from
-  // row10,etc, are need not be filled. The first iteration of 'j' fills H55-H59
-  // from row5 and H1010-H1014 from row10, etc.
-  for (int i = 5; i < wiener_win2; i += wiener_win) {
-    // Derive j'th iteration from where the H buffer filling needs to be
-    // started.
-    j = i / wiener_win;
-    int shift = 0;
-    do {
-      // Update the dgd pointers appropriately.
-      int proc_ht = v_start;
-      const int16_t *d_window = d + (i / wiener_win);
-      const int16_t *d_current_row =
-          d + (i / wiener_win) + ((i % wiener_win) * d_stride);
-      downsample_factor =
-          use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;
-      __m256i sum_h[WIENER_WIN_CHROMA] = { _mm256_setzero_si256() };
-      do {
-        UPDATE_DOWNSAMPLE_FACTOR
-
-        // Process the amount of width multiple of 16.
-        while (proc_wd < wd_mul16) {
-          const __m256i dgd =
-              _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-          const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-          INIT_H_VALUES(d_window + shift + proc_wd, 5)
-
-          proc_wd += 16;
+      // Scale M matrix based on the downsampling factor
+      for (k = 0; k < wiener_win; ++k) {
+        for (l = 0; l < wiener_win; ++l) {
+          sumY[k][l] += (sumY_row[k][l] * downsample_factor);
+          M_int32[k][l] += (M_int32_row[k][l] * downsample_factor);
         }
-
-        // Process the remaining width here.
-        if (wd_beyond_mul16) {
-          const __m256i dgd =
-              _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-          const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-          const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-          INIT_H_VALUES(d_window + shift + proc_wd, 5)
+      }
+      // Scale H matrix based on the downsampling factor
+      for (k = 0; k < WIENER_WIN2_CHROMA; ++k) {
+        for (l = 0; l < WIENER_WIN_CHROMA * 8; ++l) {
+          H_int32[k][l] += (H_int32_row[k][l] * downsample_factor);
         }
-        proc_ht += downsample_factor;
-        d_window += downsample_factor * d_stride;
-        d_current_row += downsample_factor * d_stride;
-      } while (proc_ht < v_end);
-
-      const __m256i s_h =
-          hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-      _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + (wiener_win * j)),
-                          s_h);
-      const __m256i s_m_h = convert_and_add_avx2(sum_h[4]);
-      const __m128i s_m_h0 = add_64bit_lvl_avx2(s_m_h, s_m_h);
-      _mm_storel_epi64(
-          (__m128i *)(H + (i * wiener_win2) + (wiener_win * j) + 4), s_m_h0);
-      shift++;
-    } while (++j < wiener_win);
+      }
+    }
+    for (k = 0; k < wiener_win; ++k) {
+      for (l = 0; l < wiener_win; ++l) {
+        M_int64[k][l] += M_int32[k][l];
+        M_int32[k][l] = 0;
+      }
+    }
+    for (k = 0; k < WIENER_WIN2_CHROMA; ++k) {
+      for (l = 0; l < WIENER_WIN_CHROMA * 8; ++l) {
+        H_int64[k][l] += H_int32[k][l];
+        H_int32[k][l] = 0;
+      }
+    }
   }
 
-  fill_lower_triag_elements_avx2(wiener_win2, H);
-}
-
-// The buffers H(auto-covariance) and M(cross-correlation) are used to estimate
-// the filter tap values required for wiener filtering. Here, the buffer H is of
-// size ((wiener_window_size^2)*(wiener_window_size^2)) and M is of size
-// (wiener_window_size*wiener_window_size). H is a symmetric matrix where the
-// value above the diagonal (upper triangle) are equal to the values below the
-// diagonal (lower triangle). The calculation of elements/stats of H(upper
-// triangle) and M is done in steps as described below where each step fills
-// specific values of H and M.
-// Example:
-// Wiener window size = WIENER_WIN (7)
-// M buffer = [M0 M1 M2 ---- M47 M48]
-// H buffer = Hxy (x-row, y-column)
-// [H00 H01 H02 ---- H047 H048]
-// [H10 H11 H12 ---- H147 H148]
-// [H30 H31 H32 ---- H347 H348]
-// [H40 H41 H42 ---- H447 H448]
-// [H50 H51 H52 ---- H547 H548]
-// [H60 H61 H62 ---- H647 H648]
-//            ||
-//            ||
-// [H470 H471 H472 ---- H4747 H4748]
-// [H480 H481 H482 ---- H4847 H4848]
-// In Step 1, whole M buffers (i.e., M0 to M48) and the first row of H (i.e.,
-// H00 to H048) is filled. The remaining rows of H buffer are filled through
-// steps 2 to 8.
-static void compute_stats_win7_avx2(
-    const int16_t *const d, const int32_t d_stride, const int16_t *const s,
-    const int32_t s_stride, const int32_t width, int v_start, int v_end,
-    int64_t *const M, int64_t *H, int use_downsampled_wiener_stats) {
-  const int32_t wiener_win = WIENER_WIN;
-  const int32_t wiener_win2 = wiener_win * wiener_win;
-  // Amount of width which is beyond multiple of 16. This case is handled
-  // appropriately to process only the required width towards the end.
-  const int32_t wd_mul16 = width & ~15;
-  const int32_t wd_beyond_mul16 = width - wd_mul16;
-  const __m256i mask =
-      _mm256_loadu_si256((__m256i *)(&mask_16bit[16 - wd_beyond_mul16]));
-  int downsample_factor;
-
-  // Step 1: Full M (i.e., M0 to M48) and first row H (i.e., H00 to H048)
-  // values are filled here. Here, the loop over 'j' is executed for values 0
-  // to 6. When the loop executed for a specific 'j', 7 values of M and H are
-  // filled as shown below.
-  // j=0: M0-M6 and H00-H06, j=1: M7-M13 and H07-H013 are filled etc,.
-  int j = 0;
-  do {
-    const int16_t *s_t = s;
-    const int16_t *d_t = d;
-    __m256i sum_m[WIENER_WIN] = { _mm256_setzero_si256() };
-    __m256i sum_h[WIENER_WIN] = { _mm256_setzero_si256() };
-    downsample_factor =
-        use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;
-    int proc_ht = v_start;
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i src = _mm256_loadu_si256((__m256i *)(s_t + proc_wd));
-        const __m256i dgd = _mm256_loadu_si256((__m256i *)(d_t + proc_wd));
-        const __m256i src_mul_df = _mm256_mullo_epi16(src, df_reg);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_MH_VALUES(d_t + j + proc_wd)
-
-        proc_wd += 16;
-      }
-
-      if (wd_beyond_mul16) {
-        const __m256i src = _mm256_loadu_si256((__m256i *)(s_t + proc_wd));
-        const __m256i dgd = _mm256_loadu_si256((__m256i *)(d_t + proc_wd));
-        const __m256i src_mask = _mm256_and_si256(src, mask);
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i src_mul_df = _mm256_mullo_epi16(src_mask, df_reg);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_MH_VALUES(d_t + j + proc_wd)
-      }
-      proc_ht += downsample_factor;
-      s_t += downsample_factor * s_stride;
-      d_t += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-
-    const __m256i s_m0 =
-        hadd_four_32_to_64_avx2(sum_m[0], sum_m[1], &sum_m[2], &sum_m[3]);
-    const __m256i s_m1 =
-        hadd_four_32_to_64_avx2(sum_m[4], sum_m[5], &sum_m[6], &sum_m[6]);
-    _mm256_storeu_si256((__m256i *)(M + wiener_win * j + 0), s_m0);
-    _mm_storeu_si128((__m128i *)(M + wiener_win * j + 4),
-                     _mm256_castsi256_si128(s_m1));
-    _mm_storel_epi64((__m128i *)&M[wiener_win * j + 6],
-                     _mm256_extracti128_si256(s_m1, 1));
-
-    const __m256i sh_0 =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    const __m256i sh_1 =
-        hadd_four_32_to_64_avx2(sum_h[4], sum_h[5], &sum_h[6], &sum_h[6]);
-    _mm256_storeu_si256((__m256i *)(H + wiener_win * j + 0), sh_0);
-    _mm_storeu_si128((__m128i *)(H + wiener_win * j + 4),
-                     _mm256_castsi256_si128(sh_1));
-    _mm_storel_epi64((__m128i *)&H[wiener_win * j + 6],
-                     _mm256_extracti128_si256(sh_1, 1));
-  } while (++j < wiener_win);
-
-  // The below steps are designed to fill remaining rows of H buffer. Here, aim
-  // is to fill only upper triangle elements correspond to each row and lower
-  // triangle elements are copied from upper-triangle elements. Also, as
-  // mentioned in Step 1, the core function is designed to fill 7
-  // elements/stats/values of H buffer.
-  //
-  // Step 2: Here, the rows 1, 8, 15, 22, 29, 36 and 43 are filled. As we need
-  // to fill only upper-triangle elements, H10 from row1, H80-H86 and H87 from
-  // row8, etc. are need not be filled. As the core function process 7 values,
-  // in first iteration of 'j' only 6 values to be filled i.e., H11-H16 from
-  // row1 and H88-H813 from row8, etc.
-  for (int i = 1; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN)
-
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (1 * d_stride), 6)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (1 * d_stride), 6)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + i), s_h);
-    const __m128i s_h0 = convert_32_to_64_add_avx2(sum_h[4], sum_h[5]);
-    _mm_storeu_si128((__m128i *)(H + (i * wiener_win2) + i + 4), s_h0);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN7
-  }
-
-  // Step 3: Here, the rows 2, 9, 16, 23, 30, 37 and 44 are filled. As we need
-  // to fill only upper-triangle elements, H20-H21 from row2, H90-H96 and
-  // H97-H98 from row9, etc. are need not be filled. As the core function
-  // process 7 values, in first iteration of 'j' only 5 values to be filled
-  // i.e., H22-H26 from row2 and H99-H913 from row9, etc.
-  for (int i = 2; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN)
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (2 * d_stride), 5)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (2 * d_stride), 5)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + i), s_h);
-    const __m256i s_m_h = convert_and_add_avx2(sum_h[4]);
-    const __m128i s_m_h0 = add_64bit_lvl_avx2(s_m_h, s_m_h);
-    _mm_storel_epi64((__m128i *)(H + (i * wiener_win2) + i + 4), s_m_h0);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN7
-  }
-
-  // Step 4: Here, the rows 3, 10, 17, 24, 31, 38 and 45 are filled. As we need
-  // to fill only upper-triangle elements, H30-H32 from row3, H100-H106 and
-  // H107-H109 from row10, etc. are need not be filled. As the core function
-  // process 7 values, in first iteration of 'j' only 4 values to be filled
-  // i.e., H33-H36 from row3 and H1010-H1013 from row10, etc.
-  for (int i = 3; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN)
-
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (3 * d_stride), 4)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (3 * d_stride), 4)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + i), s_h);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN7
-  }
-
-  // Step 5: Here, the rows 4, 11, 18, 25, 32, 39 and 46 are filled. As we need
-  // to fill only upper-triangle elements, H40-H43 from row4, H110-H116 and
-  // H117-H1110 from row10, etc. are need not be filled. As the core function
-  // process 7 values, in first iteration of 'j' only 3 values to be filled
-  // i.e., H44-H46 from row4 and H1111-H1113 from row11, etc.
-  for (int i = 4; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN)
-
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (4 * d_stride), 3)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (4 * d_stride), 3)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + i), s_h);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN7
-  }
-
-  // Step 6: Here, the rows 5, 12, 19, 26, 33, 40 and 47 are filled. As we need
-  // to fill only upper-triangle elements, H50-H54 from row5, H120-H126 and
-  // H127-H1211 from row12, etc. are need not be filled. As the core function
-  // process 7 values, in first iteration of 'j' only 2 values to be filled
-  // i.e., H55-H56 from row5 and H1212-H1213 from row12, etc.
-  for (int i = 5; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN)
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (5 * d_stride), 2)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (5 * d_stride), 2)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + i), s_h);
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN7
-  }
-
-  // Step 7: Here, the rows 6, 13, 20, 27, 34, 41 and 48 are filled. As we need
-  // to fill only upper-triangle elements, H60-H65 from row6, H130-H136 and
-  // H137-H1312 from row13, etc. are need not be filled. As the core function
-  // process 7 values, in first iteration of 'j' only 1 value to be filled
-  // i.e., H66 from row6 and H1313 from row13, etc.
-  for (int i = 6; i < wiener_win2; i += wiener_win) {
-    // Update the dgd pointers appropriately and also derive the 'j'th iteration
-    // from where the H buffer filling needs to be started.
-    INITIALIZATION(WIENER_WIN)
-    do {
-      UPDATE_DOWNSAMPLE_FACTOR
-
-      // Process the amount of width multiple of 16.
-      while (proc_wd < wd_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (6 * d_stride), 1)
-
-        proc_wd += 16;
-      }
-
-      // Process the remaining width here.
-      if (wd_beyond_mul16) {
-        const __m256i dgd =
-            _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-        const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-        const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-        INIT_H_VALUES(d_window + proc_wd + (6 * d_stride), 1)
-      }
-      proc_ht += downsample_factor;
-      d_window += downsample_factor * d_stride;
-      d_current_row += downsample_factor * d_stride;
-    } while (proc_ht < v_end);
-    const __m256i s_h =
-        hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-    xx_storel_64(&H[(i * wiener_win2) + i], _mm256_castsi256_si128(s_h));
-
-    // process the remaining 'j' iterations.
-    j++;
-    CALCULATE_REMAINING_H_WIN7
-  }
-
-  // Step 8: Here, the rows 7, 14, 21, 28, 35 and 42 are filled. As we need
-  // to fill only upper-triangle elements, H70-H75 from row7, H140-H146 and
-  // H147-H1413 from row14, etc. are need not be filled. The first iteration of
-  // 'j' fills H77-H713 from row7 and H1414-H1420 from row14, etc.
-  for (int i = 7; i < wiener_win2; i += wiener_win) {
-    // Derive j'th iteration from where the H buffer filling needs to be
-    // started.
-    j = i / wiener_win;
-    int shift = 0;
-    do {
-      // Update the dgd pointers appropriately.
-      int proc_ht = v_start;
-      const int16_t *d_window = d + (i / WIENER_WIN);
-      const int16_t *d_current_row =
-          d + (i / WIENER_WIN) + ((i % WIENER_WIN) * d_stride);
-      downsample_factor =
-          use_downsampled_wiener_stats ? WIENER_STATS_DOWNSAMPLE_FACTOR : 1;
-      __m256i sum_h[WIENER_WIN] = { _mm256_setzero_si256() };
-      do {
-        UPDATE_DOWNSAMPLE_FACTOR
-
-        // Process the amount of width multiple of 16.
-        while (proc_wd < wd_mul16) {
-          const __m256i dgd =
-              _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-          const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd, df_reg);
-          INIT_H_VALUES(d_window + shift + proc_wd, 7)
-
-          proc_wd += 16;
+  const int64_t avg_square_sum = (int64_t)avg * (int64_t)avg * pixel_count;
+  for (k = 0; k < wiener_win; k++) {
+    for (l = 0; l < wiener_win; l++) {
+      const int32_t idx0 = l * wiener_win + k;
+      M[idx0] =
+          M_int64[k][l] + (avg_square_sum - (int64_t)avg * (sumX + sumY[k][l]));
+      int64_t *H_ = H + idx0 * wiener_win2;
+      int64_t *H_int_ = &H_int64[idx0][0];
+      for (m = 0; m < wiener_win; m++) {
+        for (n = 0; n < wiener_win; n++) {
+          H_[m * wiener_win + n] = H_int_[n * 8 + m] + avg_square_sum -
+                                   (int64_t)avg * (sumY[k][l] + sumY[n][m]);
         }
-
-        // Process the remaining width here.
-        if (wd_beyond_mul16) {
-          const __m256i dgd =
-              _mm256_loadu_si256((__m256i *)(d_current_row + proc_wd));
-          const __m256i dgd_mask = _mm256_and_si256(dgd, mask);
-          const __m256i dgd_mul_df = _mm256_mullo_epi16(dgd_mask, df_reg);
-          INIT_H_VALUES(d_window + shift + proc_wd, 7)
-        }
-        proc_ht += downsample_factor;
-        d_window += downsample_factor * d_stride;
-        d_current_row += downsample_factor * d_stride;
-      } while (proc_ht < v_end);
-
-      const __m256i sh_0 =
-          hadd_four_32_to_64_avx2(sum_h[0], sum_h[1], &sum_h[2], &sum_h[3]);
-      const __m256i sh_1 =
-          hadd_four_32_to_64_avx2(sum_h[4], sum_h[5], &sum_h[6], &sum_h[6]);
-      _mm256_storeu_si256((__m256i *)(H + (i * wiener_win2) + (wiener_win * j)),
-                          sh_0);
-      _mm_storeu_si128(
-          (__m128i *)(H + (i * wiener_win2) + (wiener_win * j) + 4),
-          _mm256_castsi256_si128(sh_1));
-      _mm_storel_epi64((__m128i *)&H[(i * wiener_win2) + (wiener_win * j) + 6],
-                       _mm256_extracti128_si256(sh_1, 1));
-      shift++;
-    } while (++j < wiener_win);
+      }
+    }
   }
-
-  fill_lower_triag_elements_avx2(wiener_win2, H);
 }
 
 void av1_compute_stats_avx2(int wiener_win, const uint8_t *dgd,
@@ -1492,49 +707,19 @@
                             int v_start, int v_end, int dgd_stride,
                             int src_stride, int64_t *M, int64_t *H,
                             int use_downsampled_wiener_stats) {
-  const int32_t wiener_halfwin = wiener_win >> 1;
-  const uint8_t avg =
-      calc_dgd_buf_avg_avx2(dgd, h_start, h_end, v_start, v_end, dgd_stride);
-  const int32_t width = h_end - h_start;
-  const int32_t height = v_end - v_start;
-  const int32_t d_stride = (width + 2 * wiener_halfwin + 15) & ~15;
-  const int32_t s_stride = (width + 15) & ~15;
-  int16_t *d, *s;
-
-  // TODO(Diksha): Move this allocation at frame level.
-  // The buffers 's' and 'd' are used to hold (src-avg) and (dgd-avg)
-  // information respectively. Here, these buffers are calculated beforehand and
-  // used to fill M and H buffers. The buffer size required is calculated based
-  // on maximum width (i.e., from foreach_rest_unit_in_tile() 1.5 times the
-  // RESTORATION_UNITSIZE_MAX) and height allowed for wiener filtering. The
-  // width and height aligned to multiple of 16 is considered for intrinsic
-  // purpose.
-  d = aom_memalign(
-      32, sizeof(*d) * 6 * RESTORATION_UNITSIZE_MAX * RESTORATION_UNITSIZE_MAX);
-  s = d + 3 * RESTORATION_UNITSIZE_MAX * RESTORATION_UNITSIZE_MAX;
-
-  // Based on the sf 'use_downsampled_wiener_stats', process either once for
-  // UPDATE_DOWNSAMPLE_FACTOR or for each row.
-  sub_avg_block_avx2(src + v_start * src_stride + h_start, src_stride, avg,
-                     width, height, s, s_stride, 0);
-
-  // Compute (dgd-avg) buffer here which is used to fill H buffer.
-  sub_avg_block_avx2(
-      dgd + (v_start - wiener_halfwin) * dgd_stride + h_start - wiener_halfwin,
-      dgd_stride, avg, width + 2 * wiener_halfwin, height + 2 * wiener_halfwin,
-      d, d_stride, 0);
   if (wiener_win == WIENER_WIN) {
-    compute_stats_win7_avx2(d, d_stride, s, s_stride, width, v_start, v_end, M,
-                            H, use_downsampled_wiener_stats);
+    compute_stats_win7_opt_avx2(dgd, src, h_start, h_end, v_start, v_end,
+                                dgd_stride, src_stride, M, H,
+                                use_downsampled_wiener_stats);
   } else if (wiener_win == WIENER_WIN_CHROMA) {
-    compute_stats_win5_avx2(d, d_stride, s, s_stride, width, v_start, v_end, M,
-                            H, use_downsampled_wiener_stats);
+    compute_stats_win5_opt_avx2(dgd, src, h_start, h_end, v_start, v_end,
+                                dgd_stride, src_stride, M, H,
+                                use_downsampled_wiener_stats);
   } else {
     av1_compute_stats_c(wiener_win, dgd, src, h_start, h_end, v_start, v_end,
                         dgd_stride, src_stride, M, H,
                         use_downsampled_wiener_stats);
   }
-  aom_free(d);
 }
 
 static INLINE __m256i pair_set_epi16(int a, int b) {